China's Midea Group has made a formal offer for Kuka (OTCPK:KUKAY) in face of criticism by some of the robot maker's investors and German politicians.

The €115 a share price represents a significant premium to Kuka's latest closing price of €106.05 and trading levels before news of the possible tie-up first emerged. Terms of the $5B offer include a minimum acceptance rate of 30%.

Midea has also reiterated its intent for Kuka to retain its independence.